Reversing switching circuit for automatic headlight control



March 1, 1960 G. w. ONKSEN REVERSING SWITCHING CIRCUIT FOR AUTOMATIC HEADLIGHT CONTROL Filed July 2, 1956 .Sfi lflii I ATTORNEY BY eoz e 216 2253622 INVENTOR.

United States Patent REVERSING SWITCHING CIRCUIT FOR AUTO- MATIC HEADLIGHT CONTROL George W. Onksen, Anderson, Ind.,' assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application July 2, 1956, Serial No. 595,190 2 Claims. (Cl. 315-83) This invention relates to control switching means for electric lighting systems and more particularly to control switching means for multifilament headlamps for automotive vehicles.

Automotive vehicles are conventionally equipped with headlamps having a bright or long range filament for country driving and a dim or short range filament for city driving. A manually operated ratchet type foot switch is provided to alternately energize the dim or the bright filaments dependent upon the driving requirements. More recently automatic light controlled means have been offered for switching between dim and bright filaments, which means is controlled by the amount of incident light projected on the front of the vehicle to a photocell mounted behind the windshield. In installations of automatic light sensitive control means it is desirable that the driver be able to obtain either automatic control or manual control of the headlamp filament energization and also to be able to obtain the opposite beam illumination at any time, whether the headlamp filaments are under manual or automatic control.

It is therefore an object in making this invention to provide control switching means for combined automatic light sensitive and manually controlled multiple filament headlamps.

It is a further object to provide control switching means for multifilament headlamps which will always provide alternate filament energization upon actuation whether the filaments are controlled by automatic light sensitive means or other means.

It is a still further object to provide control switching means giving reverse beam illumination upon actuation at any time for automatically controlled multifilament headlamps.

With these and other objects in view which will become apparent as the specification proceeds, my invention will be best understood by reference to the following specification and claims and the illustrations in the accompanying drawings, in which the drawing is a circuit diagram of a control switching system embodying my invention.

Referring now more particularly to the drawing, there is shown therein a pair of multifilament headlamps 2 and 4, each of which has a low beam or dim filament 6 or 8, and a high beam or bright filament 10 or 12 respectively. The energization of the beams for eitherlong or short range illumination may be controlled by a conventional ratchet type foot switch 14 which remains in its last actuated position oscillating between two contacts. The switch consists of a movable armature 16 which may contact either stationary contact 18 or 20 and, as mentioned, remains in its last actuated position. Armature 16 is grounded and contact 20 is connected through line 22 with one terminal of an operating coil 24 of a relay switch 26. A pair of pivoted armatures 28 and 30 are mechanically connected togetherbut electrically insulated from each other and are simultaneously moved by energization of the relay coil 24. Armature 30 is grounded and adapted in one position to engage stationary contact 32 and in its opposite position to engage stationary contact 34. Armature 28, on the other hand, oscillates between two stationary contacts 36 and 38. Stationary contacts 34 and 36 are electrically connected together and through line 40 to the output of a light controlled amplifying device 42 which may be of the type disclosed in Patent No. 2,679,616, issued May 25, 1954, to Onksen et al.

In this type of light controlled circuit current flows in the output line 40 when no light falls on the light sensitive device and the current in line 40 is reduced upon the incidence of light on the light sensitive device. A relay operating coil 44 has one terminal connected through line 46 with the movable armature 28 of the relay 26, the other terminal of said coil 44 being connected through line 48 with a power supply 50 which is connected to a source of D.C. power such as the vehicle battery in order to supply increased voltage and provide a satisfactory voltage for the relay coil 44. Battery 52 likewise has one terminal connected through line 54 to the remaining terminal of the operating coil 24 of the relay 26. The sensitive relay 56 includes not only the operatnig coil 44 connected as previously described, but also a movable armature 58 which oscillates between two fixed contacts 6% and 62. Armature 58 is also connected to a suitable source of low voltage power 64 which may be the same storage battery of the vehicle or an additional low voltage battery, depending upon supply requirements.

Battery 64 is also connected through line 66 with movable armature 68 of a power relay 70. The power relay is provided with an actuating coil 72, one terminal of which is grounded and the second terminal connected through the line 74 with stationary contact 62 of the sensitive relay 56. Armature 68 of the power relay 70 likewise oscillates between two fixed contacts 76 and 78, contact 76 being connected through line 86 with the two dim filaments 6 and 8 and stationary contact 78 being connected through line 82 with the two bright filaments 10 and 12. All three of the relays 26, 56 and 70 are spring biased in the direction shown and pulled to the opposite position by the energization of the respective relay coils.

A reversing relay 84 is also provided which is a snapover center type and remains in the last position to which it was actuated. This relay includes two operating coils 86 and 88 for throwing the armature 90 in one direction or the other. This armature oscillates between two stationary contacts 92 and 94 and is electrically connected through line 96 to stationary contact 38 of the foot relay switch. Stationary contact 92 of the reversing relay 84 is unconnected electrically but stationary contact 94 is connected through a limiting resistance to ground. Operating coil 86 for the reversing relay 84 has one terminal connected through line 98 to line 82 and its other terminal connected through tie line 100 to conductive line 102 extending between stationary contact 32 of the foot relay switch 26 and one terminal of the other operating coil 88 of the reversing relay 84. The remaining terminal of coil 88 is connected through line 104 to line 80.

The main object of this circuit is, as previously stated, to provide the driver with an automatically controlled system in which by action of the standard type of ratchet foot switch, alternate energization of the filaments can always be obtained. In other words, regardless of which of the filaments 68 or 10-12 are energized, and further regardless of whether the light controlled amplifier' 42 or the ordinary manual control is responsible for such energization, actuation of the foot switch 14 will always provide reverse filament energizationf This operation will now be described in detail.

Assuming that the foot switch 14 is in the position shown with the movable armature 16 engaging stationary contact 18, the operating coil 24 of the relay 26 is unenergized, since its circuit is not complete. Thus its armatures 2 8 and 30 are in the upper position shown. This, however, completes a circuit from the lightico'ntrolled amplifier 42 through the sensitive relay, allowing the light controlled amplifier to control the energization and deenergization of the sensitive relay coil 44. The system is, therefore under automatic control. if no light falls on the photocell, then as previously de scribed a maximum amount of current flows in line 40, energizing coil .44, which causes it to attract its armature 58 and close a circuit with stationary contact 62. This completes an obvious energizing circuit to the power relay coil 72, causing it to attract its armature 68 and move it tothelower position, engaging stationarycontact 78. The circuit to the upper beam filaments is therefore completed as follows: from ground, through battery 64, line 66, armature 68, contact 78, line 82, filaments and 12, to ground. Thus as long as no light falls on the light controlled amplifier 42, the high beam filaments are energized through the circuit just traced. V

In the event that light does fall on the amplifier 42, current flowing in line 40 decreases and relay coil 44 will release its armature 58. This breaks the circuit to the power relay coil 72 and it likewise releases its armature 68 which moves to the back contact 76, breaking engagement with contact 78. This opens the supply circuit to high beam filaments 1% but closes the circuit to the lower beam filaments 6 and 8. Thus as long as light falls on the light controlled amplifier circuit, the low beam filamentswill be energized. Assuming that the latter condition exists, and that the relay armatures 58 and 68 are in the positions shown which provides low beam energization, and the driver Wishes high beam energization, he therefore simply actuates the foot switch 14. Armature 16 then moves to engage contact completingan obvious supply circuit for the relay coil 24, which now attracts its'armatures 28 and 30. The movement of armature 28 to contact the lower stationary contact 38 disconnects the light controlled amplifier output from relay coil 44 and that tends to deenergize the coil. However,

this has no immediate efiect since the sensitive relay was deenergized previously. Movement of the armature 30 to its lower position engaging contact 34 grounds out the light controlled amplifier and makes it insensitive. Engagement ofarmature 28'with stationary contact 38, however, completes a circuit through line 96 to armature 98 which, as was previously mentioned, is of the snapover type, remaining inits last operated position, which will be assumed to be on the right-hand side engaging Y stationary contact 94. A circuit is therefore completed for the sensitive relay coil 44 through limiting resistance 95 to ground. This circuit is from battery 52, power supply 59, line 48, coil' 44, line 46, armature 28, stationary contact 38, line 96, armature 90, contact 94, resistor 95 to ground. This will energize the coil 44, causing it toiattract its armature 58 into engagement with stationary contact 62, completing an energizing circuit for the power relay coil 72 which attracts its armature 68 into engagement with stationary contact 78 and the high beam energizing circuit will be completed. Thus the system is switched from low beam to high beam illumination by the actuation of the foot switch 14 while he automatic light controlled circuit still calls for low beam illumination;

Assuming that no change is made in the light controlled circuit and the operator wishes to return to low beam energization, he therefore reactivates the foot switch 14,

which returns to the positionshown in the drawing, breake ing the energizing circuit for the relay coil 24 and permitting armatures 28 and 30 to be withdrawn into engagement with their upper'contacts. This completes the circuit from the light controlled amplifier through line 40 and armature 28 to the sensitive relay coil 44 and breaks the previously traced circuit for coil '44 through armature 28 and stationary contact 38. Since it was assumed that the light controlled amplifier had reduced the conductivity to a point where the relay coil 44 was not strong enough to attract is armature, armature 58 now is pulled back to its upper position, deenergizing the power relay coil 72 and causing armature 68Ito be released and switch back to low beam energization. This switching also completes a grounding circuit for the reversing relay coil 88 which can be traced from energized line 80, line 104, relay coil 88, line 102, stationary contact 32, armature 30, to ground. Relay coil "88, therefore, is now energized. However, it had been assumed that armature 90 already was in its light-hand position and therefore the energization of coil 88 will not have any effect.

If the operator now desires again togo to high beam illumination and still assuming no change in the incident light conditions, he operates the foot switch 14 to move the armature 16 again into its lower position. The relay coil 24 is energized to attract its armatures 28 and 30 and the same cycle will be repeated as previously described in detail to switch to high beam illumination. If, however, the incident light conditions have changed so that the incident light has beenremoved from the amplifier 42, and the automatic control dictates high beam illumination, then with the foot switch 14 in theposition shown, the output of the light controlled amplifier 42 .will per-' mit increased current to flow through the sensitive relay coil, causing it to attract its armature 58, energizing power relay coil 72 to cause it to move its armature 68 downwardly and provide high beam illumination. As it switches to high beam illumination, the line 82 becomes energized, and this completes an energizing circuit for reversing relay coil 86. This circuit may be traced as follows: line 82, line 98 coil 86, line 100, line 102,

contact 32, armature 30 to ground. Coil 86, therefore,

attracts armature 90 away from stationary contact 94 7' and into engagement with stationary contact 92. Having now automatically switched to high beam illumination, and with incident light still removed from the light ture 90 will'remain in the left-hand position to which it was moved- Thus movement of armature 28 downwardly into engagement with stationary contact 38 now does not complete a circuit to ground for the sensitive relay coil 44 and its armature 58 moves back to its deenergized position as shown, and the lights are switched to low beam operation.

It is therefore obvious that with the disclosed circuit, regardless of the requirements of the light controlled amplifier to attempt to define which of the filaments shall be energized, any actuation of the foot switch 14 will always cause a deenergizationof the filaments currently energized and an energization of the opposite or alternate filaments.

I claim:

l. A control system for vehicle headlamps comprising a pair of headlamp circuits, a voltage source, a control relay adapted to cause energization of one or the other of the headlamp circuits, voltage supply means having one terminal connected with said control relay, a manually controlled selector switch having a first movable contact connected with the'control relay and selectively engageable in first and second positions with first and second fixed contacts, respectively, a light controlled device connected between the first fixed contact and the other terminal of the voltage supply means whereby headlamp circuit selection is determined by the light controlled device when the selector switch is in the first position, a

reversing relay having a movable contact connected with the second fixed contact and having a fixed contact connected to the other terminal of the voltage supply means, whereby headlamp circuit selection is determined by the condition of the reversing relay when the selector switch is in the second position, said selector switch including a second movable contact connected with the other terminal of the voltage supply means and engaging a third fixed contact in said first position, said reversing relay including a pair of energizing coils having a common terminal connected with said third fixed contact, the other terminal of one of said coils being connected to one headlamp circuit and the other terminal of the other of said coils being connected to the other headlamp circuit whereby the reversing switch movable contact engages its fixed contact when one headlamp circuit is energized and disengages its fixed contact when the other circuit is energized so that the control relay energization is changed whenever said selector switch is moved from said first position to said second position.

2. A control system for vehicle headlamps comprising a pair of headlamp circuits, a voltage source, relay means having an energizing circuit and a pair of fixed contacts respectively connected with said pair of headlamp circuits and a movable contact selectively engageable with the fixed contacts and connected with the voltage source, voltage supply means having one terminal connected with said energizing circuit, a manually controlled selector switch having a first movable contact connected with the energizing circuit and selectively engageable in first and second positions with first and second fixed contacts, respectively, a light controlled device connected between the first fixed contact and the other terminal of the voltage supply means whereby headlamp circuit selection is determined by the light controlled device when the elector switch is in the first position, a reversing relay having a movable contact connected with the second fixed contact and having a fixed contact connected to the other terminal of the voltage supply means, whereby headlamp circuit selection is determined by the reversing relay when the selector switch is in the second position, said selector switch including a second movable contact connected with the other terminal of the voltage supply means and engaging a third fixed contact in said first position, said reversing relay including a pair of energizing coils having a common terminal connected with said third fixed contact, the other terminal of one of said coils being connected to one headlamp circuit and the other terminal of the other of said coils being connected to the other headlamp circuit whereby the reversing switch movable contact engages its fixed contact when one headlamp circuit is energized and disengages its fixed contact when the other circuit is energized so that the energization of the relay means is changed whenever said selector switch is moved from said first position to said second position, said second movable contact of the selector switch being connected with the first fixed contact thereof when the selector switch is in the second position whereby the light controlled device is disabled.

References Cited in the file of this patent UNITED STATES PATENTS 

